A Praying Life by Paul Miller is without question the best book I've ever read on prayer. It affected me deeply. Recently, Desiring God interviewed Miller asking him about the impact his father made on his life in regards to prayer. Among other things he said,
"[It] was his emphasis on the gospel as something that Christians need to believe, that our weakness is the door to grace. I simply took that insight and applied that to my prayer life."
Isn't that sweet? In essence he's saying that prayer is simply the point where our weakness meets God's grace ... like a little child calling out to his strong daddy for help.
Let that in today ... come weak ... and pray.